Physiology lecture 3

Question 1

does diffusion of gases across respiratory membrane require energy consumption?

Answer 1

no its passive

Question 2

diffusion of gases determined by what two laws

Answer 2

Fick’s and Henry’s

Question 3

what are the factors of Fick’s law

Answer 3

thickness of respiratory membrane
surface area
diffusion coefficient
partial pressure difference

Question 4

thickness of respiratory membrane relationship to rate of diffusion and what is smth that decreases it

Answer 4

inverse proportional

pulmonary edema and fibrosis

Question 5

surface area relationship to rate of diffusion and what is smth that decreases it

Answer 5

directly proportional

lobectomy and emphysema

Question 6

diffusion coefficient relationship to rate of diffusion

Answer 6

directly proportional

Question 7

what does diffusion coeff depend on

Answer 7

solubility coef and molecular weight of gas

Question 8

diffusion coef relationship to molecular weight and solubility coeff

Answer 8

molecular weight inverse

solubility coef direct

Question 9

is the diffusion coef high or low for gases with low molecular weight

Answer 9

high and high rate of diffusion

Question 10

arrange gases which diffuses faster to slowest

Answer 10

CO2 then O2 then N2

Question 11

Partial pressure difference relationship to rate of diffusion

Answer 11

directly proportional

Question 12

as partial pressure of gas increase the rate of diffusion ……

Answer 12

increase

Question 13

partial pressure of oxygen in alveoli and in pulmonary capillary and what is the pressure gradient

Answer 13

alveoli 100
capillary 40
pressure gradient 60

Question 14

partial pressure of carbon dioxide in alveoli and in pulmonary capillary and what is the pressure gradient

Answer 14

alveoli 40
capillary 45
pressure gradient 5

Question 15

what is henrys law

Answer 15

amount of gas dissolved is proportional to its partial pressure

Question 16

solubility of gas relationship to rate of diffusion

Answer 16

directly proportional

Question 17

what affects solubility of gas

Answer 17

temperature
solubility coeff
pressure gradient

Question 18

the pressure gradient for O2 is 10 -12 times higher than co2 but why is the diffusion rate for CO2 higher

Answer 18

CO2 has higher solubility coeff and higher diffusion coeff

Question 19

what is external respiration

Answer 19

movement of gas between alveoli and pulmonary capillary

Question 20

blood in arteriorlar end of pulmonary circulation , which gas is higher and which is lower in comparison to alveolar air

Answer 20

lower oxygen and higher co2

Question 21

blood in venular end of pulmonary circulation , which gas is higher and which is lower in comparison to alveolar air

Answer 21

same oxygen and carbon dioxide conc as alevolar air

Question 22

what are the factors driving the movement of gas

Answer 22

partial pressure gradient and solubility of gas

Question 23

the concentration of oxygen in alveoli is determined by

Answer 23

rate of oxygen absorption from alveoli to blood

rate of entry of new oxygenated air from atmosphere

Question 24

during exercise what parameters increase

Answer 24

pulmonary ventilation
pulmonary blood flow
pulmonary surface area

Question 25

what are the abnormalities affecting external respiration

Answer 25

hypoxia and anoxia

Question 26

what is hypoxia

Answer 26

low oxygen in tissues limiting metabolic activity

Question 27

what is anoxia

Answer 27

no oxygen supply to tissues leading to heart attack or CVA

Question 28

What are the factors that cause low arterial partial pressure of oxygen

Answer 28

not enough ventilation problem in gas exchange between alveoli and capillary not enough oxygen is transported in blood (carbon monoxide poisoning)

Question 29

what happens to oxygen of blood in pulmonary vein when it mixes from capillaries around it during internal respiration

Answer 29

slightly decrease

Question 30

what gas levels affect bronchiole diameter and how

Answer 30

carbon dioxide | when PCO2 in expired air increases the bronchiole diameter increase

Question 31

what gas level affect arteriole diameter and how

Answer 31

alveolar gas level high co2 and low o2 causes pulmonary arteriole constriction low co2 and high o2 causes pulmonary arteriole dilation

Question 32

what are the ways co2 is transported in blood and percentages

Answer 32

70% as bicarbonate 23% bound to hb ( carbaminohb) 7% dissolved in plasma

Question 33

the carbon dioxide bound to hb binds to what part and reversible or not

Answer 33

bind to amino group and reversibly

Question 34

what is the total percentage of co2 that diffuses into RBCs

Answer 34

93%

Question 35

each 100 ml of blood carries how many ml of CO2 and O2

Answer 35

Co2 ; 4ml | O2;20 ml

Question 36

how does bicarbonate leave RBC

Answer 36

by chloride shift (exchanged with extracellular chloride)

Question 37

what % of oxygen is transported in blood and what % in plasma

Answer 37

blood 98% | plasma 1.5%

Question 38

carbon monoxide affinity is greater or lower to hb in comparison to oxygen

Answer 38

200 times more

Question 39

what does the oxygen hb saturation curve represent

Answer 39

percentage of heme units that are bound to oxygen

Question 40

what does the curve reflect

Answer 40

increased affinity for oxygen (sigmoid)

Question 41

hb is more than 90 % saturated when PO2 is

Answer 41

more than 60 mmhg

Question 42

hb entering systemic circulation how much is it saturated

Answer 42

100%

Question 43

hb leaving body tissues how much is it saturated

Answer 43

75%

Question 44

is substantial o2 reserve present in venous blood

Answer 44

yes

Question 45

hb in blood in active muscles by how much is it saturated and what is the po2 there

Answer 45

20% | po2 = 15-20 mmhg

Question 46

at high po2 the saturation is high

Answer 46

true

Question 47

what are the factors that shift the curve to right

Answer 47

2,3 BPG low PH (high H+) high temp high pco2

Question 48

when curves shift to right , at the same partial pressure, the hb saturation will be less

Answer 48

true

Question 49

higher BPG means more oxygen will be released by hb

Answer 49

true

Question 50

if BPG drops very low hb will not release oxygen

Answer 50

true

Question 51

what limits the storage of blood

Answer 51

BPG

Question 52

What factors increase BPG

Answer 52

thyroxine NE EN Growth hormone